1. Field of the Invention
The present invention relates generally to ductwork for heating, ventilating and air conditioning (“HVAC”) systems, and in particular to a support for protecting a length of flexible ductwork from crimping.
2. Description of the Related Art
Hoses, ducts and conduits in various sizes and configurations are commonly utilized for conveying, routing and directing various substances and objects. In dynamic systems, examples of such substances include air which has been heated or cooled by heating and air conditioning equipment. In the construction industry, such systems are commonly referred to as heating, ventilating, and air conditioning (“HVAC”) systems.
Typical HVAC systems include runs of ductwork extending from the heating and air conditioning equipment to additional air handling equipment, or to distribution devices, of which supply diffusers, duct collars, duct taps, duct take-offs, register boxes, energy recovery ventilators, heat recovery ventilators and filter boxes are just examples. Additional air handling equipment examples include variable air volume (“VAV”) boxes which are located in plenum spaces in many commercial structures. Heated and cooled air is typically introduced into the occupied spaces of buildings by diffusers which direct the airflow in predetermined distribution patterns for maximizing the comfort of the occupants.
Routing ductwork from the HVAC equipment to the supply diffusers or other equipment often involves ducting routes which turn, bend and intersect with various components and with other runs of ductwork. To accommodate such curved, angled, and bent routing, flexible duct is commonly used for the final portions of the duct runs, which terminate at diffusers or other components. Flexible duct also has the advantage of being easily reconfigurable to accommodate changed space configurations and the like. Another advantage of flexible duct is that it is available with insulation to avoid condensation and energy loss during cooling operation and is therefore widely used in spaces above ceilings. Flexible duct is often used in residential attic spaces and crawl spaces because it is insulated and easily manipulated in tight spaces.
However, a disadvantage of flexible duct is that it tends to crimp when bent. For example, 90° turns into diffusers can crimp unprotected flexible ducts. Crimping tends to restrict air flow and lower overall system efficiency. HVAC equipment thus works harder and consumes more power to overcome flow resistance associated with crimped flexible ducts.
A prior art solution to the problem of flexible duct crimping at diffusers and other bending locations is to install metal elbows. However, such additional components involve additional labor and material costs, as well as the possible need to insulate the metal elbow.
Other prior art solutions involving flexible duct sleeves to protect the curve of the flexible duct do not alleviate the cost issue. Prior designs use a lot of material, are difficult to manufacture, require time to strap onto the device, and are not as cost-effective as they could be.
The present invention addresses all of the disadvantages of prior art solutions to flexible duct installations. Heretofore there has not been available a support for flexible duct with the advantages and features of the present invention.